In recent years, studies have been conducted on intelligent robots interacting with human, as opposed to robots performing a repetitive task in industrial fields. Human-Robot Interaction (HRI) technology is applied to the intelligent robots interacting with human.
HRI technology is a technology that implements an interface system for interaction and communication between human and robot. HRI technology has been researched and developed based on human recognition technology (or biometric recognition technology).
Human recognition technology is a technology that recognizes or identifies a user by using a user's face, iris, retina, fingerprint, cloth, physical appearance, voice, and signature, and its application range is getting wider in security, human identification, and identity verification.
A related art human recognition has been performed on the basic premise of user's cooperation. For example, in the case of the face recognition, the user is required to impassively stare a camera at a specific distance for several seconds, or approach his or her iris to a camera, or carefully contact his or her fingerprint to a fingerprint reader.
However, in various fields including robot's HRI field, there is an increasing need to recognize users even though they are uncooperative. That is, there is an increasing need to recognize the user by using semi biometric information such as height, face or cloth's color, which can be acquired without user's cooperation, instead of biometric information such as iris or fingerprint, which requires user's cooperation.
The human recognition using the semi biometric information is considered to allow an error to some degree and perform a minimum recognition in a corresponding application, even though the user is uncooperative in an actual everyday life environment. However, since the related art human recognition technology is greatly affected by variation of illumination, color sensitivity of a camera, angle of view, noise of a microphone, noise generated during the processing of image information and voice information, and throughput of vast data, there is a limitation in increasing an acceptance rate by using the semi biometric information, and an acceptance range is narrow and an accuracy does not reach a desired level. For example, the existing human recognition technology can merely distinguish persons in a limited identification environment (for example, less than ten persons in doors), and it has not yet been commercialized.